Semiconductor devices are used in a large number of electronic devices, such as computer, communication, consumer electronics, cars and others. Semiconductor devices comprise integrated circuits (ICs) that are formed on semiconductor wafers by depositing many types of thin films of material over the semiconductor wafers, and patterning the thin films of material to form the integrated circuits. The common active element in the ICs is a field-effect transistor (FET). In scaling down of the FET, 3-dimensional field-effect transistor, e.g., a fin-like field-effect transistor (FinFET) has been developed to reduce the required area and also maintain the function that a typical planar field-effect transistors is able to provide and.
Such scaling down has also increased the complexity of processing and manufacturing the ICs. Although existing FinFET devices and methods of fabricating FinFET devices have been generally adequate for their intended purposes, there always have demands on FinFET design in scaling down of the manufacturing the ICs.